“Customer response to the iPhone 3G has been off the charts, and we are thrilled to offer our customers in Hong Kong another way to get their hands on this revolutionary device,” an Apple spokeswoman said in an email response to questions.

I am sure that most of those unlocked iPhone 3G are being exported to the gray market in countries without an iPhone deal (like Saudi Arabia). iTechia and other stores are already selling iPhone 3G in Saudi Arabia for over 4500 SR ($1200) for the 8GB model.
Via Macworld UK.